For simplicity's sake, choose an up-tempo track with a steady 4/4 beat. In time with the music, take four steps left, than four steps right at a steady clip. Keep your torso upright.
Repeat the four-step cycle, while shifting weight on the ankles and balls of the feet. (Dancers with stiff or inflexible ankles have been known to sprinkle the talc on their dancing surface to make this easier.) This should create the effect of a side-to-side "glide." This movement is the foundation of dancing to Northern Soul.
Allow your arms and hands to follow along with the glide, but remember to keep the torso rigid. This is indicative of the Northern Soul style, which, it should be noted, is not so much about technical competency as it is energy and enthusiasm.
Improvise to the rhythm of the music. Common flourishes include traditional 1960s-era "dance craze" moves like the Mashed Potato and the Monkey, in addition to more frenetic movements like the acrobatic twists, drops and spins that would later become a staple of the late 1980s' house music scene (where many Northern Soul DJs eventually would up plying their trade). The most impressive displays of the latter are usually reserved for the "peak" (either the chorus or instrumental riff) of the song in question. Keep in mind that the average Northern Soul song is only about 3 minutes long, so once the peak has passed, repeat steps Step 1 through 4.
Try with a partner. As the Northern Soul scene evolved, clubs and like-minded fans of a particular artist or song would develop a repertoire of moves in tandem with one another. It is not uncommon to see two or more devotees of the genre dancing side-by-side with each other to particular songs at Northern Soul events in clubs or bars.